strength in both if made from Opiums which differ in strength as far as permissible under their officinal definitions.

This Vinegar of Opium deserves to retain its place because it is still largely used in Philadelphia, but this is probably its chief claim to be officinally recognized. It is almost an exact duplicate of the Wine of Opium, being of the same strength, but with different aromatics - nutmeg in the one, and cinnamon and cloves in the other. But the Deodorized Tincture is a far better preparation than either and of the same strength, and, therefore, it is difficult to understand the real use of either the Vinegar or the Wine of Opium in the presence of the Deodorized Tincture.

Of course it is possible and even probable that in rare instances. any one of these preparations might be found therapeutically more acceptable than the others, but this same probability extends to other preparations not admitted to the pharmacopoeia, but which. may be superior to the Vinegar and the Wine.

There is no doubt whatever that certain combinations of Opium. act differently and better than Opium or morphia alone, both in anodyne and hypnotic effect. That is, the Opium may be so guarded. by proper corrigents that its beneficent influences may be realized with more or less of its disturbing and hurtful after-effects. This is the object of the aromatics in these preparations, and of other corrigents in other preparations, and is also the object of deodorizing the tincture. A variation of menstruum and of aromatics may therefore probably adapt this Vinegar of Opium to single cases, which would not be so well treated by other preparations, but if so, the cases must be so rare as to be best managed by extemporaneous prescription.

ACETUM SCILLE.
VINEGAR OF SQUILL.

Squill, in No. 30 powder, ten parts.....
Diluted Acetic Acid, a sufficient quantity.

To make one hundred parts

10

........

100

Moisten the powder with thirty (30) parts of Diluted Acetic Acid, and, after the mixture has ceased to swell, transfer it to a conical glass percolator, pack it carefully, and gradually pour Diluted Acetic Acid upon it until one hundred (100) parts of filtered liquid are obtained.

Preparation Syrupus Scillæ.

This preparation is of some importance as the only source for obtaining the officinal Syrup of Squill, but it can hardly be doubted

that the latter preparation could have been as well made from the Fluid Extract, or directly from the Squill as the Compound Syrup is made. Then this Vinegar of Squill would have been unnecessary. The present preparation is about 3 p. c. weaker than the old one, and this change was made simply to bring it into a decimal relationship of 10 p. c., and into uniformity in that respect with the other aceta. But as all the others had to be altered to the same or a greater extent, and for no better reasons, and for no therapeutic reasons whatever, the change is of more doubtful utility than if all had been dismissed.

An error in the revision of 1870, which rendered that process impracticable, has been corrected in this one.

The preparation is very rarely used by physicians. It occasionally enters with advantage into cough mixtures, but much less frequently than the Fluid Extract and Syrup.

ACIDUM ACETICUM.

ACETIC ACID.

A liquid composed of 36 per cent. of absolute Acetic Acid [HC, H ̧O2; 60.—Hо,С1Н ̧ O ̧; 60] and 64 per cent. of water.

3 2

4 3

A clear, colorless liquid, of a distinctly vinegar-like odor, a purely acid taste, and a strongly acid reaction. Sp. gr. 1.048 at 15° C. (59° F.) Miscible in all proportions with water and alcohol, and wholly volatilized by heat. Acetic Acid neutralized with water of Ammonia, is colored deep red by ferric chloride, and decolorized again by strongly acidulating with sulphuric acid.

Acetic Acid should not yield a precipitate with hydrosulphuric acid (lead, copper or tin), or when supersaturated with water of ammonia (iron), or with testsolution of oxalate of ammonium (calcium). When slightly supersaturated with water of ammonia, the liquid should not exhibit a blue tint (copper), nor should any residue be left on evaporating this alkaline liquid on the water-bath (other acids and fixed impurities). When supersaturated with solution of potassa, it should not have a smoky odor or taste, and, when diluted with 5 volumes of distilled water, the color caused by the addition of a few drops of test-solution of permanganate of potassium should not be sensibly changed by standing five minutes at the ordinary temperature (abs. of empyreumatic substances). Boiled with an equal volume of sulphuric acid, the liquid should not be darkened (organic impurities). On adding a crystal of ferrous sulphate to a cooled mixture of equal volumes of Acetic and Sulphuric Acids, no brown or reddish brown zone should make its appearance around the crystal (nitric acid). No precipitate should be formed on the addition of a few drops of test-solution of chloride of barium (sulphuric acid), nor by adding to another portion some test-solution of nitrate of silver (hydrochloric acid), nor, after the last-named addition, should the mixture turn dark on being warmed (sulphurous acid).

To neutralize 6.0 Gm. of Acetic Acid should require 36 C. c. of the volumetric solution of soda.

Preparation Acidum Aceticum Dilutum.

The tests for quality and strength of Acetic Acid are very much extended and improved in this revision and now leave nothing to be desired for the easy recognition of a standard acid. The tests are all simple and easily applied by any one, and here the plan which is original with this Committee of Revision, of naming the substances tested for in parenthesis after each test, is well illustrated. This is an admirable plan and will do more to direct and facilitate the application of tests than any simple proceeding that could have been adopted.

This application of accurate tests is really one of the most important of the functions of a pharmacopœia, inasmuch as it is that which makes it a standard, and no step has ever been taken in any revision which at all compares with this of 1880 in the multiplication of simple, easy and accurate tests,-in giving the methods of application, and the objects for which they are applied. The importance of this improvement cannot be better illustrated than in the case of Acetic Acid, because the condition of the common market in regard to this article is so very loose and bad, both in quality and strength.

"Acetic Acid No. 8" is generally demanded, or commonly sold, whether demanded or not, both in the arts and for medicinal and dietetic purposes. This commerical term “No. 8" has no fixed or definite meaning. Anybody may sell any strength he pleases as "No. 8," and as there are very few who examine the strength of what they buy, while many are very close buyers by price, it happens that competition in price obtains low prices for still lower grades of strength and quality. This writer has frequently tested the acids of this market for many years past and has found the socalled "No. 8" to vary between 22 and 32 p. c. in strength, and quite as much in quality. Therefore, strength alone being taken into account, the seller of a 22 p. c. acid as "No. 8" would at 25 p. c. less price make more money on his "No. 8" than the seller of a 30 p. c. acid would, and the first would, in a majority of cases, sell his "No. 8," while it is very easy to see where the real interest of the buyer lies, namely, in paying the higher price for the stronger article, because the lower strength gets more money for the amount of acid present, and makes a better profit than the seller of the higher strength.

This designation "No. 8" originated, so far as this writer knows and believes, in the British Excise System, where one series of numbers was used for Acetic Acid, and another higher series for Vinegars, the two having no relation to each other. The meaning of No. 8 seems to have been that one part of such Acid by dilution made 8 parts of "No. 15 Vinegar," and No. 15 Vinegar contained about 4 p. c. of Acetic Acid. This would give just 32 p. c. as the proper original strength for No. 8 Acetic Acid, and the same rule would give just 48 p. c. as the strength of No. 12 Acetic Acid, and these are the only two numbers now heard of in this market in connection with Acetic Acid. The No. 8 is very common, but No. 12 is rarely heard of. By some kind of common consent among the better class of dealers, a usage has been established in this class of manufacturers and dealers of making No. 8 Acid to be about as nearly 30 p. c. as the common hydrometers and the rough usage of them by unskilled workmen can get it. Hence, from many of the better sources it is found to vary between, say 26 and 31 p. c., the average being below 30 p. c.; but from a large majority of sources the No. 8 Acid will not average over 25 p. c., and the No. 12 from 38 to 40 p. c. These lower strengths are generally of low quality also, and are commonly used in a rough, inaccurate way in the arts, especially in the arts of dyeing and calico printing. The No. 8 of better quality, such as is used in food, medicine and photography, is of late years sold by one class of dealers as nearly 30 p. c., or s. g. 1.040, as they can get it, and the s. g., but not the percentage, is generally marked on the carboys and on the labels; but the No. 8 of another class of dealers is as nearly 25 p. c. as they can get it, and has a s. g. of 1.034, but neither the percentage nor the s. g. appears on such parcels. Now if a 30 p. c. No. 8 Acid be worth 9 cents per pound as by the price lists, a 25 p. c. No. 8 is only worth 74 cents, but even in the vigorous competition of underbidding dealers, it would rarely be offered under 8 or 8 cents, so that the profit on it would be much better than on the No. 8 of 30 p. c., and beside the quality is always better the higher the strength. In ordering Acetic Acid the consumer, or the retail dealer next to the consumer, often uses no designation at all, simply ordering Acetic Acid. Others order Acetic Acid No. 8, and this is the usage of a large mass of druggists and pharmacists. Such orders will never bring an Acid of above 30 p. c., and will often bring it below 25 p. c., when really in a large proportion of the cases a 36 p. c. Acid is needed and required. Hence, it is far better, and the only proper

and safe way, to order the Acid by percentage strength only, and abandon these arbitrary numbers which really mean nothing and carry no responsibility of any kind. If an order be for 36 p. c. Acetic Acid, or for Acetic Acid U. S. P., which means 36 p. c., or for Acetic Acid 30 p. c., then there is a responsibility upon the seller, and if the strength be short the acid can be returned. In buying acid the paying for water instead of acid should be avoided. The best 36 and 30 p. c. Acids of the market are generally of about the same price in proportion to strength and quality. That is to say, if 30 p. c. Acid be quoted on the lists at 94 cents, and 36 p. c. Acid or U.S. P. Acid at 12 cents per pound, as they should be, then the price is practically the same for the amount of acid really paid for, the 12 cent strength being about cent higher for better quality incident to higher strength, because the concentration always improves the quality with the strength.

The present tests for impurities in Acetic Acid should always be applied before the tests of strength, because the presence of other acids, etc., interfere with all the tests for strength. As a rule it is now easy to get an acid in the markets at a moderate price which will satisfy all the tests, and the only impurities now commonly met with in the better grades are traces of hydrochloric acid, and more or less empyreuma, but deficiency in strength is by no means uncommon, while want of uniformity of strength within two or three p. c. is very common indeed. Hydrochloric acid is immediately detected by solution of nitrate of silver, and when traces only are present to give a faint opalescence, it may be disregarded. Empyreumatic matters are the most common and most important impurities of all the better grades of modern Acetic Acid, and no acid that is not chemically pure is entirely free from empyreuma. Most of the better grades are free enough to prevent the odor from being noticed when the acid is simply smelled, because the sharpness of the acid vapor blunts the sense of smell, so that an acid sensibly free from empyreumatic smell will, when saturated by soda or potassa, give a very decided odor. But even when the saturated acid is nearly or quite free from empyreumatic odor to an ordinary sense of smell, it is still liable to be contaminated with a small proportion of these substances. This being the case, the permanganate test is supplied in order to prevent a reliance upon the sense of smell, which is so different in different persons. The permanganate is, however, a most sensitive test, and as given in the Pharmacopoeia is too rigorous and exacting, when the acid tested is required to remain